US Bridges

Spring Road over Nubanusit Brook

Fair

Hillsborough County, New Hampshire · 0.2 MI FR Dublin Tl · Structure no. 020800500014100

Built
1940
85 years old, rebuilt 1997
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
67 ft
2 main spans
Daily traffic
214
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Spring Road over Nubanusit Brook is a steel stringer/multi-beam or girder carrying Spring Road over Nubanusit Brook in Hillsborough County, New Hampshire. It was built in 1940 and reconstructed in 1997, so it is 85 years old, older than the New Hampshire average of 56.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 214 vehicles a day, roughly 4% of them trucks, projected to reach 316 by 2043. The structure is 67 ft (20.4 m) long and 26 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

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CarriesSpring Road
CrossesNubanusit Brook
Location0.2 MI FR Dublin Tl
CountyHillsborough County
StateNew Hampshire
Coordinates42.90962, -71.99611
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating72.4 US tons
Inventory rating45 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadHS 25 or greater
Structure length67 ft (20.4 m)
Longest span29 ft (8.8 m)
Deck width26 ft (7.9 m)
Roadway width23 ft (7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic214 (2023)
Projected traffic316 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$314,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Spring Road over Nubanusit Brook built?

It was built in 1940, making it 85 years old in 2025. It was reconstructed in 1997.

What condition is Spring Road over Nubanusit Brook in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in July 2023.

How much traffic does Spring Road over Nubanusit Brook carry?

About 214 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Spring Road over Nubanusit Brook?

The structure is 67 ft (20.4 m) long with a longest span of 29 ft (8.8 m) and a deck 26 ft wide.

Who owns Spring Road over Nubanusit Brook?

It is owned by the City or Municipal Highway Agency.